Needle septum fluid interconnects have been employed in inkjet printing systems. These interconnects have used a molded elastomeric septum placed below a rigid chamber in which are placed a small metallic ball and a helical compression spring. A slit in the septum forms an opening for a side-hole needle to penetrate. A crimp sleeve held the septum in place.
Slitting the septum causes micro-tearing in the septum material, causing high stress when the septum is penetrated by the needle. When the needle is engaged, the ink can contact the septum, and can attack the high stress areas of the septum, leading to possible material property degradation and material set. Slitting the septum can result in jagged coarse surfaces. As the needle engages the septum, it can scrape septum material away, introducing small particles into the ink and thus contaminating the ink.
A septum structure includes a septum body structure fabricated of a resilient material. The body structure includes an opening formed there through and a first seal surface circumscribing the opening to engage against a needle when inserted into the opening. The body structure further includes a second seal surface for engaging against a stopper structure assembled with the seal septum when the needle is not inserted into the opening. The septum structure can be over-molded on a rigid host part, or fabricated as a separate structure from the host part, and pressed in to place. Other embodiments are disclosed.